There's another blurb in the WaPo article Andy refers to below that's worth mentioning:
Although signs of academic success are unknown--this year's round of standardized test scores has not been released--Green Dot has won praise for making the campus safer and sparking significant increases in attendance and student retention rates. That was enough for Rhee to consider Green Dot as a possible partner.
Parents often will pick a charter school over the neighborhood school for reasons of safety or class size or a host of other tangibles. This makes sense. Though we in the policy community focus on achievement, new charters often perform no better (and sometimes worse) than the neighborhood school. This lag is usually made up for after a few years, but in the meantime, parents often play up the other benefits of a well-run charter school, like feeling relatively certain their child's classmate won't bring a gun to school. It also makes sense that school safety would be an important factor for Rhee as chancellor of a notoriously violent school district. She's made some steps to reign in the most troubled schools, but there's still a long way to go. But this also underscores something else that Rhee apparently believes in: you can't have a good school until it's well-run, or put another way, student achievement depends on good management. Steve Barr's Locke Senior High School takeover might not have produced stellar test scores yet, but it has whipped the management of the school into shape. And there's something to be said for that.